Massachusetts: An unfounded report of a gunman at the Massachusetts Institute of Technology that briefly caused a campus-wide lockdown stemmed from an electronic message sent to police, authorities said.

Officers searched for a man reported to be carrying a long rifle and wearing body armor but found nothing unusual, Cambridge police said. The report turned out to be a hoax, and there was no threat to public safety, state police spokesman David Procopio said yesterday.

Cambridge police received the tip in an electronic chat message around 7:30 am, but witnesses on the scene eventually contradicted it, spokesman Dan Riviello said. MIT sent two emergency alerts via text message, urging people to stay indoors. Less than an hour later, police posted on Twitter that the scene was clear.

Investigators are trying to identify the prankster and will pursue criminal charges if they do, Riviello said. He declined to provide additional details or confirm reports that the IP address used by the prankster has been traced to New York, saying "as it is an active and ongoing investigation, I cannot release any additional information at this time."

About 11,000 people attend the prestigious school outside Boston where students are famous for their smarts as well as their stunts, including once putting a police car on top of a domed campus building.